OCTOBER 01, 2005
Jeannette Yeznach Wick, RPh, MBA

Supercalifragilisticexpialidocious: is it a drug, or a biologic? Fans of Mary Poppins will say, "Neither" ?it is a nonsense word she created to lighten children's spirits. Perhaps she has moved on in her career?to creating new drug names! The roughly 33,000 proprietary names and 9000 generic names registered in the United States1 fall short of her word's 14 syllables, but they can be just as confusing if you have never heard them pronounced or said them yourself.

Various stakeholders develop nomenclature as new agents (drugs and biologics) proceed through the development process.1 The Table lists pharmaceutical agent name types. This article emphasizes generic drug names and how they differ from brand names.

There are specific differences between generic names and proprietary drug names. Generic names average 14.4 letters and 5 syllables. Drug companies try to keep proprietary names unique and short (average, 10.4 letters and 3.53 syllables); their goal is brand name recognition.

The International Nonproprietary Names (INN) system, overseen in America by the US Adopted Names (USAN) Council, was initiated in 1950 to create generic names, and has designated more than 7000 names for pharmaceutical substances.2 Unlike brand names, generic names are selected using a system of suffixes and prefixes. The INN's goal is to develop a name with word fragments that make sense and to minimize errors. The INN registers approximately 100 generic names annually. 1 Names are based on stems (syllables common to agents sharing pharmacologic actions). For example, the stem tinib refers to tyrosine kinase inhibitors. A list of approved stems is available at

Name Confusion

Approximately 25% of errors reported to the Institute for Safe Medication Practices (ISMP) Medication Error Reporting Program involve 2 drugs with look-or sound-alike names.3 These are known as orthographic (spelling) and phonetic (sound-based) errors, respectively.3 The great similarity of generic names suggests that they may be more confusing, on average, than proprietary names.1 But, people rely on the first several letters to differentiate similar names, so unless the prefixes are the same (like the old cep-, amino-, and chlor-classes), they are less likely to be confused. The INN rarely uses prefixes anymore.4

The World Health Organization's INN Committee is the final approving authority. Lexicon problems can be complex. A name chosen in one country may already be a word in another language and, unbeknownst to the naming party, may even be offensive. Also, the letters H, J, K, or W do not exist in some of the 130 countries that use INNs, or have different sounds in various languages. Therefore, generics do not begin with these letters. The USAN Council avoids names starting with X and Z, as they often sound alike. Stems like "brev-," "vel-," and "mal-" that either mean or imply other things ("brevity," "velocity," "bad") are not allowed, either.

Demystifying Confusing Names

The USAN takes steps to decrease name confusion, and strives for shorter, pronounceable generic names. This is a challenge, especially with the new biologics. Health care professionals can take steps to prevent errors.

First, they should acknowledge that pharmaceutical companies advertise their products by trade name. Physicians refer to drugs by trade name, generic name, chemical name, or drug class. Patients often identify a drug by color, size, or shape.5 Clearly, different languages are being spoken. Physicians can help by writing trade and generic names together, and/or including the prescription's target symptoms on the prescription.

Then, pharmacists can determine if the agent is appropriate, and the indication will appear on the label for the patient or caregiver.4,5 Physicians often ask patients to bag all their medications and bring them to each office visit. The "brown bag rule" should extend to the pharmacy as well, so old containers can be checked against new prescriptions.4,5

Dispensing pharmacists can also underline the differentiating prefix on the prescription. For example, making it a habit to underline the "nad-" in nadolol or the "azi-" in azithromycin ensures that propranolol or erythromycin is not dispensed. They can also develop a "gray list" of inappropriate medications for various age groups or high-risk drugs that have high stakes when administered incorrectly.5 Pharmacists should consider using the Beers criteria for potentially inappropriate medication use in older adults6 and the ISMP list of high-alert medications (available at to craft a list appropriate for your population. When medications on these lists are prescribed, pharmacists should slow down and show extra care.

In addition, pharmacists can create a chart on an erasable white board listing generic drugs being used, the current manufacturer, and the current brand's tablet markings. If the brand changes, but the tablet is still white, the chart will reflect the new manufacturer and markings. Noting the markings on the prescription takes very little time and is an additional safety measure. If the markings do not match, something is wrong.

Finally, pharmacists should take a few minutes to report errors to the ISMP or the FDA. The FDA reviews about 250 medication errors a month and, depending on its findings, can change the way a drug product is labeled, named, or packaged.7

Patients Are Partners

The ultimate weapon against name-confusion errors is the patient. When physicians write a prescription for Lasix, and the pharmacist dispenses furosemide labeled with one of its dozens of generic proprietary names, it can be very confusing.8 Pharmacists should use generic names, and teach their patients that if they can sing "supercalifragilisticexpialidocious," they can learn generic drug names. They simply are not that difficult.

Ms. Wick is a senior clinical research pharmacist at the National Cancer Institute, National Institutes of Health, Bethesda, Md.

For a list of references, send a stamped, self-addressed envelope to: References Department, Attn: A. Stahl, Generic Pharmacy Report, 241 Forsgate Drive, Jamesburg, NJ 08831; or send an e-mail request to:


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